Stapling machine



Sept. 19, 1933. y, H. J. BAU-R 1,927,274

STAPLING MACHINE Filed April 16, 1932 UNITED STATES PATENT OFFICE STAPLING MACHINE Hugo J. Baur, Chicago, Ill., assignor, by mesne assignments, to A. L. Hansen Mfg. Co., Chicago, Ill., a corporation of Illinois Application April 16, 1932. Serial No. 605,606

3 Claims. (C1. 1 3) y The present invention has to do with stapling toward the blade 17 by a follower 21 which is admachines, and is particularly concerned with an vanced by a spring 22. improvement for incorporation in a stapling ma- When the blade 17 on the hammer is withdrawn chine oi the type disclosed in a pending appliupwardly far enough to clear the magazine 19, 5 cation of Edward Krantz led on February 28, the foremost staple in the magazine will advance' 60 1931 under Serial No. 519,212. into the guideway 18 beneath the lower edge of In order to obtain a good clinching action with the blade, in readiness to be driven downwardly suchamachine, it is important that the normally and clinched against the anvil l upon downelevatedI arm which carries the spring-actuated Ward movement of the blade.

1o staple-driving hammer be moved downwardly The hammer 15 is moved downwardly at a 65 into rmly compressed engagement with the high rate 0f Speed by the expanding aci/i011 0f a sheets of paper or other material on the anvil compressed coil spring 23, The lower end of before the hammer starts to drive the staple. the spring 23 is seated in a socket 24 in the top of The purpose of this invention is to provide the hammer, while the upper end of the spring if means for insuring that the pressure which is abuts against a plate 25 in the upper end of the 70 applied to the machine in operating the same will guideway 16. The plate 25 may be raised or cause the arm to move all of the way down to lowered in the guideway by turning a knurled the anvil before the hammer starts to drive the Screw head 26, whereby to vary the degree to staple. which the spring 23 is compressed when the 2o While the foregoing statement is indicative in hammer is raised and accordingly vary the force 75 a general way of the nature of the invention, with which the staple is driven. other more specific objects and advantages will The hammer l is raised in the guideway be apparent to those skilled in the art upon a full against the yielding resistance of the spring 23 understanding of the construction, arrangement by means of an operatinglever 27 which is pivand operation of the improved stapling machine. otally mounted on the arm 12 behind the guide- 80 In order that the invention may be readily unway 16 on a pin 28 in the front head-like portion derstood, one embodiment of the same is pre- 0f the arm. The lever 27 is provided at its rear sented herein, but it will of course be appreciated end with a hand knob 29, which knob is located that the invention is capable of being embodied a short distance in front of the pivotal connec- 30 in other structurally modified forms coming tion between the base 11 and the arm 12. A dog 85 equally within the scope of the appended claims. 30 is pivoted to the front end of the lever 27 on In the accompanying drawing: a pin 31, and the lower depending end of the Fig. 1 is a partially sectioned side view of a' dog is shaped to form a hook 32 which is adapted stapling machine in which the hereinafter deto engage against the upper edge of a recess 33 35 scribed improvement is incorporated; in the rear face of the hammer 15. The dog 30 90 Fig. 2 is a top view of the machine; and is also provided just above the hook 32 with an Fig. 3 is a vertical longitudinal section through inclined surface 34 which is adapted to cam the upper portion of the machine, showing the against the lower edge of a partition 35 at the supplemental spring which prevents any rebound back of the guideway 16 when the hammer 15 taking place at the instant that the hammer is reaches its uppermost position, whereby to force 95 released to drive the staple. the hook 32 rearwardly out of the recess 33 in In the stapling machine shown in the drawing, the hammer and allow the latter to be driven a clinching anvil l0 is mounted on the front end downwardly under the expanding action of the of an elongated base 11. An arm 12 is positioned compressed spring 23.

above the base and is pivotally connected at its The arm 12 is normally maintained in a 100 rear end to the rear end of the base by a pin 13 slightly raised position with respect to the base which is mounted in spaced side ilanges 14 on 11 by means of an upwardly spring-pressed stud the base. A staple-driving hammer 15 is slidably 36, which stud is adapted to yield when downrnounted in a guideway 16 in the front end of the ward pressure is rst applied to the knob 29, be-

SU arm 12 and is provided at its lower end with a fore the hammer 15 is raised and released under 105 narrow blade 17 which reciprocates vertically the action of the spring 23. ,After the hammer in a closely conforming guideway 18. The guide- 15 has 'been released from the dog 3U, the operway 18 intersects with a staple magazine 19 ating lever 27 is returned to its normal position which extends longitudinally of the arm 12. by means of a light wire spring 37. yThe dog 30 Staples 20 in the magazine are fed forwardly is normally pressed against the rear face of the 110 hammer 15 by means of a small wire spring 38.

The resistance offered by the main spring 23 to downward movement of the hand lever 27 is ordinarily sufficient in the Krantz machine to cause the arm 12 to move down against the material on the anvil 10 before the hammer 15 is released to drive the staple into the material, but sometimes the hammer will release before the arm is fully down, or will operate during a rebound of the arm caused by improper and careless manipulation of the lever, resulting in an unsatisfactory clinching action.

In order to prevent this, a supplemental spring 39 is provided which effectively eliminates rebound and insures uniformly satisfactory results with the machine. The spring 39 is of fairly heavy wire construction and has a laterally bent end portion 40 which is spaced below the lower edge of the lever 27 directly in the path of movement of the latter. The spring 39 may be enclosed within a small drum-like housing 41 at one side of the upper front portion of the arm, with the end 40 limited in its upward movement by an inturned tongue 42 on the rim of the housing and with its other end 43 compressed against an opposed wall of the housing. The intermediate portion 44 of the spring may be fulcrumed on the pivot pin 28.

When the lever 27, in being depressed, reaches a certain position, it will come into engagement with the end 40 of the spring 39 and the spring will be flexed by the lever before the latter in its downward movement is permitted to release the elevated hammer 15. The additional force required in causing the spring 39 to yield will be transmitted to the arm 12 and will cause the latter to be pressed rmly down against the material on the anvil at the instant that the staple is driven.

When the hammer 15, in traveling downward, reaches the lower end of the guideway 16, the

shock of the contact will be absorbed by a rubber block 45 which is fastened in a socket 46 in the bottom of the hammer in slightly projecting relation to the latter.

I claim:

1. In a stapling machine, a base which is provided with a staple clinching die, an arm which is pivoted to the base and is provided with a staple driving hammer above the die, spring means for normally maintaining the arm elevated with respect to the base to permit free insertion of paper or other material therebetween, an operating lever which is connected with the arm and is provided with a pressure receiving handle, spring means for driving the hammer and for normally maintaining the handle elevated, means for releasing the hammer to permit it to drive a. staple when the handle reaches a certain position in its downward movement, and means for causing the arm to move downwardly into operative relation to the die on the base before the handle is permitted to reach its staple-releasing position.

2. In a stapling machine, a base which is provided at its front end with a staple clinching die, an arm which is pivoted at its rear end to the rear end of the base and is provided at its front end with a staple driving hammer above the die, spring means for normally maintaining the front end of the arm elevated with respect to the front end of the base to permit free insertion of paper or other material therebetween, an operating lever which is pivotally mounted at its front end to the front end of the arm and is provided at its rear end with a pressure receiving hand knob which is located in front of and above the pivotal connection between the base and the' arm, spring means for driving the hammer and for normally maintaining the knob elevated, means for releasing the hammer to permit it to drive a staple when the knob reaches a certain position in its downward movement, and means for causing the arm to move downwardly into operative relation to the die on the base before the knob is permitted to reach its hammer-releasing position.

3. In a stapling machine, a base which is provided at its front end with a staple clinching die, an arm which is pivoted at its rear end to the rear end of the base and is provided at its front end with a staple driving hammer above the die, spring means for normally maintaining the front end of the arm elevated with respect to the front end-of the base to permit free insertion of paper or other material therebetween, an operating lever which is pivotally mounted at its front end to the front end of the arm and is provided at its rear end with a pressure receiving hand knob which is located in front of and above the pivotal connection between the base and the arm, spring means for driving the hammer and for normally maintaining the knob elevated, means for releasing the hammer to permit it to drive a staple when the knob reaches a certain position in its. downward movement, and supplemental spring means in the path of movement of the lever for additionally resisting the downward movement of the knob at a point just in advance of the hammer-releasing position for causing the arm and lever to move downwardly as a unit into a position wherein the arm will bear firmly against the material on the die.

HUGO J. BAUR.

Mil 

